b

-- b
-- Moves the turtle the specified distance backwards
-- Written by HarvDad, March 2014

args = {...}
nArgs = #args

x = 0
y = 0
z = 0
face = 0
minimumFuel = 100
abort = false
local currentFuelLevel = turtle.getFuelLevel()
distance = 1;

if (nArgs == 1 and args[1]== "help") then
	print("Moves the turtle the specified distance backwards")
	print("Usage: f [distance]")
	return
end

if nArgs == 1 then
  distance = tonumber(args[1])
  if distance == nil then
  	print(args[1], " is not a valid distance")
	return
  end
end

-- MAIN PROGRAM

turtle.select(1)

if currentFuelLevel ~= "unlimited" then
	if currentFuelLevel < minimumFuel then
		if not turtle.refuel() then
		  print("No fuel")
		  return
		end
	end
end

for i=1,distance do
	turtle.back()
end